This invention relates in general to a device for constructing elongate structures of composite materials, such as graphite/epoxy tape and in particular to devices for pulling elongate structures through a plurality of forming dies. Still more particularly, the present invention relates to such devices which include gripping means which tightens in response to increased resistance.
Devices for forming composite structures are well known in the prior art. Many such devices include one or more forming dies for forming and curing strips of epoxy coated graphite materials. It is necessary to draw the cured material through the dies utilizing a mechanical drawing device when an elongate structure is desired.
A problem exists when attempting to form elongate structures of great length in that mechanical drawing devices capable of pulling such structures through the forming dies are unduly complex and unreliable.
One solution to this problem of fabricating elongate structures is the utilization of continuous pulling devices which are capable of drawing structures of indeterminate length through forming dies. However, the utilization of such devices often generates problems when the grip of the device on the elongate composite structure is either too loose, resulting in slippage and uneven curing of the resultant structure, or is too tight, resulting in damage to the resultant structure.
It is therefore obvious that a need exists for a continuous pulling device which is capable of positively gripping an elongate composite structure and increasing the tightness of that grip in response to increased resistance of the elongate composite structure.